Mercedes-Benz NOx Sensor A0091530728 5WK96657A 12V Original Quality

Mercedes diesel NOx sensor, OEM numbers A0091530728 and 5WK96657A, installed on the exhaust pipe adjacent to the SCR system. It continuously monitors nitrogen oxides in the exhaust and feeds data to the ECU to precisely control urea injection, ensuring emissions compliance and protecting the aftertreatment system. Fits many Mercedes models with OM642 or OM651 engines, including W204, W212, W166. Installation difficulty is medium; estimated labor 0.5-1 hour. Avoid damage to sensor wiring.